W _ W - unpflrotation
US006765544B1
(12) United States Patent
(10) Patent N0.:
US 6,765,544 B1
(45) Date of Patent:
Jul. 20, 2004
Wynne Willson
(54)
IMAGE PROJECTION APPARATUS AND
6,099,128 A
*
METHOD WITH VIEWING SURFACE
6,144,483 A
* 11/2000 Allen et a1. ..... ..
DEPENDENT IMAGE CORRECTION
6,208,318 B1 *
3/2001 Anderson et a1.
6,215,499 B1 *
4/2001
6,219,093 B1
4/2001 Perry
(75) Inventor: Peter David Wynne Willson, London
8/2000 Jessl ......................... .. 353/51
(*)
Notice:
IiZuka
.. 359/618
9/2002
6/2002 Nishida
Kakimoto
et et
a1.a1.............. .. 353/98
FOREIGN PATENT DOCUMENTS
Subject to any disclaimer, the term of this
patent is extended or adjusted under 35
USC. 154(b) by 296 days.
GB
2 265 064
JP
9/1993
07-5566 A
*
WO 98/18037
4/1998
W0
WO 98/18040
4/1998
G02B/27/28
W0
WO 99/41544
8/1999
......... .. F21V/17/02
* cited by examiner
(22) Filed:
Primary Examiner—Amr AWad
Oct. 20, 2000
.......... .. H04N/5/74
1/1995
W0
(21) Appl. N0.: 09/692,417
(30)
............ ..
353/85
6,443,576
6,409,350 B1 *
(73) Assignee: Wynne Willson Gottelier Limited,
Kent (GB)
345/1.1
Neff et a1. ................ .. 345/419
6,310,726 B1 * 10/2001
(GB)
359/305
......... .. G02B/26/10
(74) Attorney, Agent, or Firm—Sterne, Kessler, Goldstein
Foreign Application Priority Data
& FOX P.L.L.C.
Sep. 8, 2000
(GB) ........................................... .. 0022065
(57)
(51)
Int. Cl.7 ................................................ .. G09G 5/00
(52)
(58)
US. Cl.
.... .. 345/6; 353/51; 359/197
Field of Search ........................ .. 345/6—9; 359/196,
359/197, 212, 206, 210, 223; 353/50, 51,
99
ABSTRACT
Lighting apparatus comprises a de?ector to de?ect a light
beam from a video projector in a plurality of directions, (ii)
image processing means to process image information and
comprising an input to receive raW image information from
an image source, a processor to process the raW image
(56)
information into processed image information, and an output
to output processed image information to the video
projector, and (iii) a controller that controls operation of the
processor of the image processing means according to the
References Cited
U.S. PATENT DOCUMENTS
4,663,698 A
5,793,340 A
5/1987 Tomlinson
*
8/1998 Morita et a1. ................ .. 345/7
5,828,485 A
5,982,525 A
status of the de?ector.
10/1998 Hewlett
11/1999 Matsubara et a1.
9 Claims, 6 Drawing Sheets
100
Axis of rotation
Ellipsoidal re?ector 106
W
_
""“‘€"'"'"“
/
Ob‘ecti Le
J
W
I
>
112
116
W m
/DoubleMirrorassy. 114
-
unpflrotation
.
\-1l8
u
-
i
v
"lmagcEngine
102 mp1“
108
120
Prism
no
122
124
f‘ Axis of rotation
126
'
U.S. Patent
Jul. 20, 2004
Sheet 1 6f 6
US 6,765,544 B1
~14
26“
__,_____.-—p
Fig. 1
(Prior Art)
U.S. Patent
Sheet 3 0f 6
Jul. 20, 2004
US 6,765,544 B1
Double M'il'l’ol' Orbital
{3/- Automated Focus/
201'
/2o2
DATAB
207
Image
203
DATAZ
DATA]
/
'204
/
212
211
Graphics
-
Objm- Image
Store
uononooo
'nnooooo
'-
H
)
U.S. Patent
Jul. 20, 2004
Sheet 4 6f 6
US 6,765,544 B1
“N“ED
“
8
0
3
9
5
8
o
?
3
m
a
g
[email protected] E
. M53696.2
5M
.ME
4
U.S. Patent
Jul. 20, 2004
Sheet 5 6f 6
US 6,765,544 B1
Fig. 5
Locate Home
Position
t
Con?gure for
_
Correct Aspect
Graphxcs Engme
Ratio
Load Image
.
1'
a
PUI
.
Check 1'9‘
Attribute Positional Data
Change 111
. Attribute
\ Feedback from Attribute
Perform
‘
Attribute
Algorithm
'
'
v
Output to Video
Projector
.
U.S. Patent
Jul. 20, 2004
Sheet 6 6f 6
Zero Ref
X: Y1
US 6,765,544 B1
Zero Raf
X4 Y4
W T7
J ‘n
Fig. 7
Xdh
US 6,765,544 B1
1
2
IMAGE PROJECTION APPARATUS AND
METHOD WITH VIEWING SURFACE
DEPENDENT IMAGE CORRECTION
artWork, an image library, static and moving images, vector
and bit map images, full-streaming video (VCR, Vcam),
data output from a PC and the like. Suitable storage includes
?oppy disk, optical disk, DVD, mini-disk and videotape.
The present invention provides apparatus optionally in
BACKGROUND OF THE INVENTION
modular or kit form that modi?es or updates eXisting video
projection systems. The apparatus suitably has connections
1. Field of the Invention
This invention relates to image projection apparatus and
to lighting apparatus for use in conjunction With image
so as to intercept the data output from the graphics store, that
is to say the input signal to the projector, optionally further
10
projection apparatus, in particular to apparatus for projecting
dynamic images.
to de?ect the light beam output from the projector. The
2. Related Art
In the entertainment lighting industry, Wide ranges of
apparatus are knoWn for creating lighting effects With both
process that data and then pass the data on to the projector.
The apparatus includes a de?ector Which is positioned so as
de?ector may as a side effect of de?ecting the beam impart
15
static and movable and controllable spotlights and there are
a host of devices for altering the output of these lights; these
distortion to the image When its direction of projection is
altered. The function of the image processor is to introduce
a correction to the image data in anticipation of the distortion
plastic ?lters. Video and slide projectors are also increas
ingly used to enhance the range of techniques available to
that occurs as a result of passing through the de?ector. The
function of the processor is optional in as much as the
correction can be turned off or on according to the type of
effect Wanted. It is in addition optional to use the image
designers of entertainment, promotion, advertising and cor
processor deliberately to distort the image and/or to super
porate presentations.
impose further and different effects upon the raW or cor
devices include diffusers, gobos and coloured glass and
WO 98/18040 describes a light projector and associated
methods of achieving various effects.
Aproj ector based upon an array of digital micromirrors is
rected data. With knoWledge of the video image desired to
be seen on the vieWing surface, the controller can direct
25
made by Texas Instruments Inc., of Dallas, TeX., USA, and
US. Pat. No. 5,828,485 describes uses of such a projector in
obtaining gobo effects.
using knoWn video projection equipment, effects not envis
aged or imagined in design of the projectors. Projectors can
be used dynamically to project images onto different vieW
ing surfaces, switching from surface to surface and scanning
images across surfaces Whilst the apparatus continuously
Afurther device is knoWn from W0 98/ 18037 in Which a
beam is re?ected from a mirror and an image generator is
moved in tandem With movement of the mirror so as to
correct for distortion caused by the movement of the mirror.
Designers at the current time seek ever to introduce
further innovation in the effects they achieve through neW
combinations of eXisting equipment and faster and more
accurate control of that equipment.
appropriate processing by the processor according to the
status of the de?ector.
It is thus the case that the apparatus of the present
invention enables a Wide variety of effects to be achieved
35
corrects for image distortions caused by movement of the
de?ector. Still and moving images can be moved like
scenery Without the need for heavy equipment or multiple
projection systems.
The image processing means can comprise a ?rst memory
SUMMARY OF THE INVENTION
The present invention seeks to provide and open up a neW
to store the raW image information and a second memory to
40
?eld of light and image projection, both using static and
dynamic images, and thus including video projection as Well
as stage and other lighting effects.
Accordingly, the present invention provides, in a ?rst
aspect, lighting apparatus, comprising:
45
a de?ector to de?ect a light beam in a plurality of
store the processed image information. The contents of the
second memory are then used for generation of the image by,
for eXample, a projector.
In use, the de?ector rotates an image in the projection
beam as a consequence of de?ecting the beam, and a
function of the controller is to direct the processor to process
the raW image information so as to provide a correction
therefor in the processed image information. It is an advan
tage that as a result the projected video image can therefore
directions;
image processing means to process image information,
comprising an input to receive raW image information,
remain upright.
It may further be necessary to correct keystoning of the
a processor to process the raW image information into
image, introduced eg by a tilted single mirror or by the
processed image information, and an output to output
projection beam striking the screen at an angle, and a
processed image information; and
a controller that controls operation of the processor of the
image processing means according to the status of the
de?ector.
This apparatus is especially useful in combination With a
suitable correction may be achieved using a pair of prisms
or a moveable lens Which enable horiZontal and vertical
55
keystone to be corrected independently. Alternatively, key
stoning maybe corrected by adjusting the image during or
after image generation. Hence, it is further preferred that the
apparatus is arranged such that When the de?ector introduces
a keystone effect into an image in the light beam the
video projector and an image source, designed for static
projection of an image onto a vieWing surface. In operation
of one such knoWn projector, data in an image source such
controller directs the processor to process the raW image
as a graphics store is fed to the projector input, processed by
the projector to form a projection beam and then projected.
information so as to provide a correction therefor in the
processed image information. In apparatus that is especially
preferred, there is provided the option that When the de?ec
Focus and Zoom controls are included on the projector as per
usual. Using a personal computer (PC) an eXtensive range of
images can be produced. The graphics store is typically in
computer memory, in or adjacent the projector or remote
from the projector, and used to store imagery, such as
tor both rotates an image in and introduces a keystone effect
65
into an image in the light beam the controller directs the
processor to process the raW image information so as to
provide corrections for both distortions in the processed
US 6,765,544 B1
3
4
image information. In this Way these tWo separate distor
receives image information of an image to be projected. The
joining of a projector to this apparatus provides a system for
tions are dealt With.
light projection that greatly increases the uses and versatility
of knoWn projectors, providing a system With capabilities
Well beyond anything envisaged for a static projector. Inputs
to the image processor and video projector are suitably in
accordance With the DVI protocol.
Asecond aspect of the invention makes possible mechani
Aparticular apparatus of the invention also has means to
correct the focus according to the direction of projection,
and this correction is optionally achieved by moving an
objective lens of the image projector. The correction may be
calculated With reference to the distance from the image
projector to the surface, and this distance may be measured
cal correction for rotation of an image by use of a double
using a distance detector such as an electronic range-?nding
device utilising the Doppler-shift effect, With a sensor
mounted on the image projector. The focus correction may
also be knoWn from calibration of the equipment and
pre-programmed so that When the de?ectors of the apparatus
10
a de?ector to defect a projection beam in a plurality of
directions;
beam correction means to impart rotation of an image in
are directed to de?ect the beam in a given direction the
distance to the vieWing surface is knoWn and the required
focus adjusted according to a look-up table or similar. As
Will be appreciated by those in this art, the focusing means
may be located in the path of the light beam betWeen the
projector and ?rst light de?ection means. Alternatively, the
focusing means may be located in the path of the light beam
mirror head. Accordingly, apparatus of the second aspect
comprises:
15
the beam; and
a controller that directs the degree of rotation imparted by
the beam correction means according to the status of
the de?ector.
Image processing means can be included, to process
image information, said image processing means comprising
an input to receive raW image information, a processor to
betWeen the ?rst and second light de?ection means. As
another alternative, the focusing means may be located in
process the raW image information into processed image
information, and an output to output processed image
information, Wherein the de?ector introduces a keystone
effect into the image and the controller directs the image
the path of the light beam to focus the image de?ected by the
second light de?ection means. The processor can thus be
programmed in softWare so as to direct the status of the 25 processing means to process the raW image information so
focusing means according to the status of the de?ector. The
as to provide a correction for that keystone effect in the
controller may also direct the status of the focusing means
processed image information. In this Way, there is mechani
according to the distance along the beam from the apparatus
to a vieWing surface. This enables dynamic changes in focus,
cal rotation correction and softWare keystone correction.
As With the apparatus of the ?rst aspect, focusing means
through continuous feedback from a distance ?nder associ
can be incorporated into the apparatus so the controller
directs the status of the focusing means according to the
ated With the apparatus to the controller folloWed by output
of an appropriate focusing signal, either to its oWn focusing
status of the de?ector, or the controller can comprise an
means or to that of the projector, Whilst the output of the
projector is moved from one vieWing surface to another. A
further embodiment of the invention provides controlling
inputs to a dynamic iris, preferably also by feedback to/from
output for outputting focus information to a projector, and
35
according to the status of the de?ector, or the controller
comprises an output for outputting Zoom control information
to a projector according to the status of the de?ector.
the controller.
Similarly, the apparatus can further comprise Zoom con
trol means, With the controller directing the status of the
Zoom control means according to the status of the de?ector
or the distance along the beam from the apparatus to a
A third aspect of the invention provides apparatus in
40
can be output to Zoom equipment of the apparatus or to
external Zoom equipment such as on a projector eg to
accordingly comprises:
45
image processing means to process image information
and comprising an input to receive raW image
information, a processor to process the raW image
mirrors are particularly suitable, so that the beam can be
information into processed image information, and an
re?ected in substantially any direction according to the
respective positions of the mirrors. In apparatus described
output to output processed image information;
a beam generator to generate a light beam from the
beloW in more detail, there is a ?rst light de?ection means
arranged to rotate about a ?rst aXis and a second light
de?ection means arranged to rotate about a second aXis
processed image information;
a de?ector to de?ect the light beam in a plurality of
directions; and
substantially orthogonal to the ?rst aXis, and this is some
times referred to as a double mirror head. The ?rst and
second light de?ection means may also comprise ?rst or
second rotatable lenses. An advantage of a double-mirror
Which the elements described above are incorporated into
one apparatus rather than by combining together various
individual units. Projection apparatus of the third aspect
vieWing surface. As With focus information, Zoom signals
maintain the desired image siZe or introduce special effects.
Preferably, the de?ector has tWo moveable de?ectors,
the apparatus can include Zoom control means and the
controller directs the status of the Zoom control means
55
a controller that controls operation of the processor of the
image processing means according to the status of the
de?ector.
image processor eg to keep the image upright and free of
Optional and preferred features of the apparatus of the
?rst and second aspects, related to image processing,
de?ector(s), controller, focus control and focusing means,
keystone.
Zoom control and Zoom means, distance detection and others
type de?ector is that the image remains orthogonal after
being de?ected, simplifying the correction(s) needed by the
For ready use of the lighting apparatus With a projector,
the apparatus can also include coupling means for securely
coupling the lighting apparatus to a projector in such a
are similarly optional and preferred features of apparatus of
the third aspects.
position that the light beam output from the projector passes
Which rotation correction is mechanical, and comprising:
through the de?ector of the lighting apparatus and so that the
output of the image processing means of the lighting appa
ratus can be coupled to an input on the projector that
A fourth aspect provides light projection apparatus in
65
a beam generator to generate a light beam
a beam correction means to impart rotation of an image in
the beam;
US 6,765,544 B1
6
5
ments betWeen projecting ?rst and second images, offering
a signi?cant increase in ?exibility for the operator. With the
a de?ector to de?ect the light beam in a plurality of
directions; and
a controller that controls the rotation imparted by the
present invention it is possible to create effects that are quite
beam correction means according to the status of the
de?ector.
different from and go far beyond presently available effects,
in that dynamic video images can be projected onto and
Optional and preferred features of the apparatus of the
?rst and second aspects, related to image processing,
de?ector(s), controller, focus control and focusing means,
around, say, individuals on stage and tracked across the stage
or across the vieWing surface Without distortion of the
image. It is further possible to fade, rotate, shift or morph
from one image to another, for eXample With one image
Zoom control and Zoom means, distance detection and others
are similarly optional and preferred features of apparatus of
the fourth aspects.
A ?fth aspect of the invention provides a method of
projecting an image in a light beam, comprising:
superimposed on another for a part of the time betWeen
changing from one image to the neXt—all effects not achiev
able using knoWn apparatus.
generating the light beam;
de?ecting the light beam of a de?ector, the de?ector being
15
moveable so as to de?ect the beam in a plurality of
directions, an effect of de?ecting the beam being to
rotate the beam; and
prior to de?ecting the beam, imparting a rotation of the
beam to correct for the rotation caused by de?ecting the
beam.
An effect of de?ecting the beam can be to change the
lighting apparatus comprises ?rst and second rotatable light
de?ection means for de?ecting a light beam in different
directions, the beam being de?ectable by the ?rst light
de?ection means on to the second light de?ection means so
as to de?ect the beam in substantially any direction. Thus,
for eXample, a double mirror-containing head is used to
direct the beam in any direction, at the control of the
distance from the de?ector to a surface on Which the image
is vieWed, and the method preferably comprises adjusting
the focus of the beam according to the change in distance.
A further effect of de?ecting the beam can be to change the
25
is vieWed, Wherein the method preferably comprises adjust
ing the Zoom of the beam according to the change in distance
to maintain the image siZe on the screen. Astill further effect
of de?ecting the beam can be to introduce a keystone effect
By providing separate image rotation means, the degree
into an image in the beam, wherein the method preferably
comprises, prior to de?ecting the beam, introducing a cor
rection to the keystone imparted by the de?ecting of the
of rotation of the image can be carefully controlled, and
effects as described in more detail beloW achieved.
35
References to a projector are intended to include reference
to projectors that include lenses and optical elements, pro
jection engine components the output of Which may be
electrical. Suitable projectors may include cathode ray tubes,
light valve technology, the Texas Instruments Inc. DLP
In particular, the apparatus may be used to project an
image contained in the light beam in many directions. An
image producing device, referred to sometimes as the object,
may be placed in the optical path to shape the light beam
40
(registered trade mark) projection engine relying upon a
DMD (digital micro mirror, registered trade mark) chip,
liquid crystal devices such as polysilicon LCD panels (P-Si),
produced by the light source, or a video image may be
projected. As the pan and tilt in the double mirror head are
rotated, the image projected by the apparatus moves spa
tially. HoWever, if the image is projected, for eXample,
horiZontally and sWept about a vertical aXis, Without a
compensating rotation of the image by the image rotation
optionally With Micro-Lens arrays or other re?ective LCD
devices such as JVC’s direct drive light ampli?er (D-ILA).
Using the apparatus described, an image can be projected
operator. Data feedback from the head as to the relative
positions of the mirrors can be used to calculate and control
the degree to Which a correcting rotation and/or keystone is
introduced into the image. Alternatively, the head can be
instructed to direct the beam in a given direction and
knoWledge of that direction and the resultant correction
required can be used to control the degree of correction to be
made.
distance from the de?ector to a surface on Which the image
beam.
The present invention aims to provide novel means for
moving an image over a surface and adjusting that image
according to hoW it is moved over the surface, alloWing for
rotation, keystone, focus and Zoom effects. Preferably, the
45
means (the processor or the beam correction means) the
projected image appears to rotate about the longitudinal aXis
of the beam. This Would be problematic When the image is
asymmetrical; for eXample, if the projected image is a face,
the face Would appear to rotate With the sWeeping of the light
beam. The present invention thus avoids this unWanted
against a concave surface, such as the inside of a sphere in
a specially designed vieWing area With location for specta
tors proXimal to the projector.
The apparatus can also be used to project an image onto
a stage, such as a theatre stage, moving the de?ector so as
problem.
to move the image about the stage. One eXample of the
invention in action comprises moving the beam so that it
Preferably, the apparatus further comprises control means
for controlling the rate of rotation of the image by the image
folloWs an actor as he or she moves about. A scene repre
rotation means. The control means may be arranged to
senting movement of an actor, say, in a car is readily 55 calculate a required rate of rotation of the image by the
image rotation means from the rate of rotation of each of the
achieved With projection of a static or moving background
?rst and second light de?ection means.
onto and around the actor; as the actor moves across the
stage so the background may also folloW the actor, resulting
In a preferred embodiment, rotation of the image in one
direction by the image rotation means is adapted to com
pensate for rotation of the image in the other direction due
to de?ection thereof by the ?rst and second light de?ection
means. This can enable an asymmetric image to be sWept by
in a neW and visually pleasing effect not achievable hitherto.
Another eXample of the invention in action comprises
using apparatus to project an image onto the stage at a
predetermined position, thereafter turning off the projecting
means, or dimming or obscuring the output, moving the
de?ector and thereafter projecting an image, optionally a
different one, at a second predetermined position. Use of the
invention in this Way reduces the need for separate lights for
the separate images, or reduces the need for manual adjust
360 by 360 degrees (global projection) With substantially no
65
rotation of the image about the longitudinal aXis of the beam,
rotation of the image due to de?ection thereof by the ?rst
and second light de?ection means being automatically com
pensated by rotation of the image rotation means.
US 6,765,544 B1
7
8
In use of the present invention, an asymmetric image, for
example a video image, is moved over a vieWing surface
video image emanating from substantially any direction.
The recorder is preferably a video camera.
Without rotation of the image perceived by the spectator. As
In a speci?c embodiment of the invention, the video
a spectator Watches, the image remains in an upright orien
camera is a security camera. The invention thus enables the
tation. In addition to, or as an alternative to, eliminating any
security camera to be securely mounted Whilst movement of
the image rotation means and the light de?ection means
rotation of the image, the image rotation means may be
arranged to introduce a desired rotation of the image. This
enable pictures from substantially any direction to be
can produce spectacular optical effects; for eXample, the
recorded. The camera itself can for eXample be mounted
inside or behind a Wall, and thus made more remote from
projected image can be sWept through a given angle and onto
different angled surfaces at different distances from the
object projector With substantially no rotation thereof, and
then rotated through any chosen angle Whilst the mirrors in
10
the head remain still.
To maintain an image upright as it moves across a surface,
the rotation of the image rotation means needed to compen
sate for rotation of the image due to de?ection off the
de?ectors may be calculated from the respective movements
15
and more secure from tamper. Using the image rotation
means, Whether electrical or mechanical, to compensate for
rotation of the image due to de?ection off the de?ection
means has the result that an upright image can be recorded
Whatever its origin relative to the stationary camera.
It is further preferred that the recording apparatus includes
focusing and Zoom control means according to the ?rst and
of the ?rst and second light de?ection means. Alternatively,
second aspects of the invention, to enable adjustment of
using appropriate softWare, the compensating rotation may
focus and Zoom according to the distance from the apparatus
be obtained from a pre-calculated look-up table. Another
to the subject being recorded. In conjunction With focus and,
option is to use a correction as described in WO 98/18037.
or Zoom control a distance detector can be provided for
One mechanical option is that the image rotation means
comprises a rotatable dove prism or other mechanical device
dynamic adjustment of these parameters.
BRIEF DESCRIPTION OF THE FIGURES
or mirror equivalent. If so, the control means may be
arranged to control the rotation of the dove prism about the
longitudinal aXis of the light beam.
The apparatus may further comprise beam generating
means for generating the light beam and beam shaping
means for altering the shape of the light beam to generate the
image in the light beam. The beam shaping means may
comprise a selective light re?ecting or transmitting device.
The invention is noW described in speci?c embodiments
25
FIG. 1 shoWs a schematic vieW of a knoWn beam steering
apparatus;
FIG. 2 shoWs the optical path in an embodiment of image
projecting apparatus of the invention;
This can enable the shape of the image to be dynamically
controlled. The light re?ecting device can comprise a plu
rality of digitally controllable micromirrors, P-Si With a
FIG. 3 shoWs a schematic diagram of a further embodi
ment of projection apparatus of the invention;
FIG. 4 shoWs a schematic control system;
FIG. 5 shoWs a schematic diagram of operation of a
micro-lens array, D-ILA or any other suitable image delivery
system.
The present invention also provides a method of project
ing an image in a light beam by de?ecting the beam using
35
de?ect the beam substantially in any direction, the method
DETAILED DESCRIPTION OF THE
PREFERRED EMBODIMENTS
40
EXAMPLE 1
using image rotation means.
Preferably, the method further comprises the step of
controlling the rate of rotation of the image by the image
rotation means. The rate of rotation of the image by the
image rotation means may be calculated from the rate of
rotation of each of the ?rst and second light de?ection
Double Mirror Head
Apparatus for directing a beam of light by rotatable
45
means.
Preferably, rotation of the image due to the de?ection
thereof by the ?rst and second light de?ection means is
compensated by the rotation of the image by the image
rotation means. In one preferred embodiment, the image
rotation means comprises a rotatable dove prism.
A further aspect of the invention provides video image
recording apparatus, comprising
projection system; and
FIGS. 6 and 7 shoW calculation of keystone correction.
?rst light de?ection means on to second light de?ection
means, and rotating both light de?ection means so as to
comprising the step of rotating the image in the light beam
With reference to the accompanying draWings in Which:
55
a video image recorder;
?rst and second rotatable light de?ection means for
mirrors is knoWn from US. 4,663,698 and is illustrated
schematically in FIG. 1. The apparatus comprises a ?rst
mirror 10 on a rotating ?rst support, or “pan”, 12 Which is
mounted to apparatus body 14. The body 14 includes a light
source, such as a lamp 16, and focusing arrangement 18.
Using a belt drive, the pan 12 is rotatable about pan aXis 20
by a motor 22 mounted on the body 14.
Asecond mirror 24 on a rotating second support, or “tilt”,
26 is mounted on the pan 12. Using another belt drive, the
tilt 26 is rotatable about tilt aXis 28, orthogonal to the pan
aXis 20, by a motor 30 mounted on the body 14. This
arrangement of rotatable mirrors can direct a beam of light
in many directions and is used for moving a White or
de?ecting light in different directions, the light being
coloured light beam. Beam steering apparatus using a pair of
de?ectable by the ?rst light de?ection means on to the
second light de?ection means; and
image rotation means for rotating an image in the light;
rotatable mirrors is also described in our co-pending Inter
national patent application no. WO 99/41544, the contents
of Which are incorporated herein by reference.
Wherein the ?rst and second light de?ection means can be
so moved as to de?ect light from substantially any
EXAMPLE 2
direction through the image rotation means and into the
video image recorder.
This confers the advantage that the video image recorder
can be statically mounted but nevertheless used to record a
65
Image Projection Apparatus
With reference to FIG. 2, the optical path of an embodi
ment of an image projecting apparatus is shoWn generally as
US 6,765,544 B1
9
10
100. The apparatus comprises a beam source 102 for gen
erating a beam of light. As shown in FIG. 2, the beam source
circuitry is arranged to calculate the required rate of rotation
of the dove prism 110 from the rates of rotation of the pan
116 and tilt 122. In addition to compensating for rotation of
the image due to de?ections thereof in the beam steering
apparatus 114, rotation of the dove prism 110 may be
separately controlled to produce a desired rotation of the
102 comprises a lamp 104 and an ellipsoidal (or other
concave-shaped) re?ector 106, the lamp 104 being situated
at the focus of the re?ector 106 to provide a broad, parallel
beam of light. Instead of being a parallel beam, the beam
may be converging or diverging, the apparatus including, if
desired, suitable means for focusing the beam.
The light beam generated by the beam source 102 is
incident upon an image generating engine 108, Which alters
the shape of the light beam to generate an image in the light
beam. The engine 108 may take any suitable form; eXamples
include a digitally controllable light re?ecting device. Such
projected image. Feedback from the beam steering apparatus
114 via a processor (not shoWn) to the image engine addi
10
tionally provides correction in the image engine for key
stoning introduced by the beam steering apparatus. Feed
back as to the distance to a vieWing surface is used to adjust
the focus by objective lens 112.
a digitally controllable device is available from TeXas
Instruments, Inc., and typically comprises a plurality of
digitally controllable micromirrors Which are selectively
moveable to either de?ect light aWay from the optical path,
EXAMPLE 3
15
Referring to FIG. 3, a projection system 200 comprises a
tWin aXis, double mirror, orbital head With universal mount
ing 201, focus and Zoom mechanics incorporated Within the
in Which case a dark region appears in the resultant projected
image, or toWards the optical path. Red, green and blue
scales in the image can be obtained by the modulating the
device at high speed, and moving a colour Wheel in the light
path. Typically, the micromirror device is operated at three
times the normal speed and the resultant red, green and blue
images are integrated by the human eye into a colour image.
The image output from the engine 108 is incident upon a
dove prism 110. The prism 110, having a different refractive
Projection System
head assembly (not shoWn), means for positional feedback
25
to/from the orbital head, via DMX through link 202, to direct
the head position and to feedback the position of the head,
output and input via DMX through link 203 to/from a
computer controller 205 having a WindoWs operating sys
tem embedded in a proprietary video-graphics softWare
indeX to air, refracts the light beam as shoWn in FIG. 2, With
platform, and a controller 205. The apparatus is resident on
the result that the image in the light beam is laterally
inverted. The principle of the dove prism is Well knoWn and
hard disks, and a S-VGA VGA, XGA, S-XGA, UXGA or
a high speci?cation, rack-mounting, PC With high capacity
higher resolution video graphics cards. A laptop computer
based lighting controller, or lighting desk, is also suitable
With resident cueing indeX providing to images resident in
Will not be discussed further.
The image output from the dove prism 110 is focused by
objective lens 112 onto beam steering apparatus 114. In the
embodiment shoWn in FIG. 2, the beam steering apparatus
the PC.
The double mirror head is shoWn coupled to the output of
comprises a pan 116 including a ?rst planar re?ector 118,
such as a mirror, the pan 116 being rotatable about pan aXis
120.
Atilt 122 is mounted on the pan 116 and includes a second
planar re?ector 124, such as a mirror, and is rotatable about
a tilt aXis 126 substantially orthogonal to the pan aXis 120 so
that the mirrors can direct light in substantially any direction
35
40
for projection through an aperture in the tilt 122. The planar
re?ectors, or parts thereof, may comprise a plurality of
mirrors at different angles to each other, forming a mosaic of
mirrors. At least part of one or both mirrors may comprise
a diffuser. As an alternative to planar re?ectors, the pan 116
and tilt 122 may include any suitable means for de?ecting
a video projector 206. The head incorporates focusing and
Zoom lenses, under control of motors Whose operation is in
turn controlled via inputs from the master controller. Motors
to control the positions of the mirrors are likeWise under
control by the master controller and feed back is in place as
to the position of the mirrors in the head from the head to the
master controller.
Image processing means 207 has an input 208 for image
data from the graphics store 210 and an output 209 for
sending processed data to the projector 206. Aseparate input
45
via DMX through link 203 receives instructions from the
the light beam, such as lenses.
In addition to, or alternative to, the objective lens 112, one
controller as to the processing to be carried out on the image
data from the graphics store. The controller has an output
204 to a monitor 212 to enable the operator to see the effects
or more beam focusing means, such as lenses, may be
being projected or to be projected in future. The controller
arranged at any suitable point Within or eXternal of the beam
has an input 202 from the head and an output to both the
head and to the image processing means via link 203 and a
separate RS232 link 211 With the graphics store 210. Eth
steering apparatus 114.
As discussed above, if the image projected from the beam
steering apparatus 112 is sWept about, for eXample, a vertical
aXis, the image rotates about the longitudinal aXis of the light
beam due to the de?ections of the image Within the beam
steering apparatus. In order to compensate for this rotation
of the image, the dove prism 110 is rotated about aXis 128
co-aXial With the longitudinal aXis of the light beam incident
thereon. This rotation of the dove prism 110 has the result of
ernet and ?reWire type links are eXamples of industry
standards links for use in the invention.
55
rotating the image output from the dove prism 110. By
co-ordinating the rate of rotation With the rates of rotation of
the pan 116 and tilt 122, the rotation of the image by the
dove prism 110 can compensate for the rotation of the image
due to the de?ections thereof Within the beam steering
apparatus 114.
The dove prism 110 may be rotated by any suitable means
under the control of suitable control circuitry. The control
In use, image data is provided to the image processing
means from the graphics store in the PC. The controller
directs a signal to motors of the head to effect an orientation
of the mirrors of the head so as to de?ect the beam from the
projector in a chosen direction. Data as to the orientation of
the mirrors is provided to the controller as a feed back to
con?rm their positions. The controller directs a processing
signal to the image processing means, Which processes the
image data so as to introduce a correction for the expected
65
rotation and keystone effects that are the result of passing
through the double mirror head. The controller also directs
a signal to the motors of the head that control focusing and
Zoom lenses on the head to ensure the projected image is at
US 6,765,544 B1
11
12
a desired focus and a desired Zoom. The image is projected
With desired orientation, focus, Zoom and appearance. It is
also possible for the controller to send instructions to the
head and the image processor at the same time, in Which case
feedback from the head can be omitted.
it is preferred to incorporate as much of the processing
functions in eXisting hardWare (i.e. the PC graphics engine
platform and the lighting desk).
There are three principle options available for the PUI,
and Whilst the folloWing are quite different, they incorporate
all the elements of the control system as depicted in FIG. 4.
Management of the images is carried out in a system using
the folloWing elements:
Option 1: PUI—The Controller
In this option, the lighting desk is the controller With sole
control of all attributes. As Well as the primary output
A library: This holds the images on a remote PC, one per
head. There may be a very large number of these images. A
the sequences and acts as the backdrop upon Which to hang
channels to control focus, Zoom, pan and tilt there are also
several dedicated data channels designed to call up pre
de?ned cues on the graphics engine. All input processing is
thus a function of the desk, feedback is a closed loop system
Within the head.
Option 2: Attributes via CPU In this version all the
attributes are a function of the CPU (the CPU also acting as
the PUI) With a separate user interface combining attribute
the images, this element being the main point of interaction
control and graphics editing. The shoW is programmed using
betWeen user and apparatus.
trigger points at cue changes on the timeline that in turn are
A previeW screen: In conjunction With the timeline, this
provides a Way of visualising the shoW. This previeW screen
can play through the sequence, applying the transformations
operator thus has no direct control through the desk of any
in the sequence de?ned in the timeline.
gers.
Way of searching for images using keyWords via an eXternal
10
controller, one per system, can be incorporated.
An editor: This enables the user to open up any image and
edit it accordingly. For example, it alloWs the user to add and
edit teXt to library images.
A timeline: This provides a schematic representation of
15
triggered by the lighting desk via DMX. The lighting
attributes other than blind programming the required trig
Option 3: Custom System
Pre-programmed transforms: The majority of transforma
tions are accessible from the user interface, any transforma
25
tion Which is envisaged as being often used is easily found
and incorporated.
is programmed and operated independently of any other
controllers, although it is possible to accept eXternal triggers
User-de?nable transforms: For users to create and incor
porate their oWn transforms into the softWare and to have
if used as part of a timecoded shoW.
these accessible easily.
Attributes
Control of the image via softWare is achieved, so that
A description of the principle attributes is detailed beloW
orientation, keystone/perspective correction, rotation,
direction, speed and other manipulations are all be available
via the graphics package resident in the rack-mounted PCs.
The head is controlled by 16-bit DMX 512 to 12-bit
resolution driven by a hybrid stepper motor and driver.
Smooth travel, accuracy, and repeatability preferably take
priority over high speeds. A feedback interface optionally
alloWs the image orientation to be synchronised to the
position of the head.
Programmable focus is carried out by mechanics resident
in the head assembly, and controlled by DMX. Integrated
control is carried out from a laptop installed With proprietary
The ?nal option is a completely standalone system that
controls imageering, attributes and feedback With a suitable
graphical user interface, also acting as the PUI. This system
With reference to FIG. 5.
Tilt. The tilt operation is straightforWard. Currently there
35
is a 12 bit signal available Where the control ampli?er senses
incremental or decremental values for direction. 12 bit
resolution is thus available for both clockWise (T) and
counter-clockWise (T‘) rotation.
Pan. The pan operation is slightly more complex due to
40
the mechanical pan/tilt summation. Whilst the same is true
for resolution and direction sensing to give 12 bit resolution
for clockWise (P) and counter-clockWise (P‘) rotation, the tilt
head also needs to rotate in the same sense and velocity as
the pan head, if the pan is to rotate With no change in tilt
lighting control surface. Another control method is to use a 45 position. This can either be a function of the CPU or an error
correction level to the feedback circuit of the tilt.
knoWn desk, such as the Flying Pig Systems Wholehog
(registered trademark) desk. Use of such a lighting control
One
Focus.
is to use
There
a simple
are three
pre-programmable
options available
focus
WithWhich
focustakes
desk can also provide access to an image library, for
selection and cueing of images and application of video
an Nbit data signal to give IN/ZbII resolution from an
arbitrary mid-point. The second option is to use a mecha
tronic range ?nding system Which uses an optical device to
adjust focus, such as that found in a camera. In practice
though, such a mechanism may prove to be ineffective When
effects.
EXAMPLE 4
Control Structure
The control structure includes tWo features, namely that
trying to focus on a uniformly coloured screen With no
55
identi?able relief. The third option is to use the CPU to
calculate focal position based on spatial information already
input to the processor, and real time positional information
both the focus and Zoom attributes are Wholly inclusive
elements of the proposed control system, With attendant
drive systems. Similarly, keystoning is also taken to be an
from the PUI.
Zoom. Zoom is a straightforWard attribute With control
from the PUI. The control signal is again in the form of an
independent operation of the video projector; although all
three of these elements may be satisfactorily controllable via
an interface to the chosen projector, that may not alWays be
Nbit data signal giving IN/ZbII resolution from an arbitrary
the case.
mid-point.
Principal User Interface (PUI)
Rotation. There are tWo options available for rotation (R)
of the image. One is to perform an opto-mechanical trans
form based on the home position of the head and the default
image orientation set in the imaging softWare. As the pan
and tilt rotate the image is contra rotated to keep it in the
This is made up of a traditional lighting desk, a computer
based graphics engine and some form of image processor
function (in this case a CPU) to combine the tWo and drive
the head. Anumber of options eXist for the processor, though
65
US 6,765,544 B1
14
13
correct orientation at all times. The second is to use a
software algorithm to perform the same task based on
-continued
default spatial coordinates.
Table of Functions Required
It is also a requirement to have a manual override of
rotation direction and speed in the PUI to give the ?exibility
to the designer of rapid image manipulation rather than
Attribute
relying on performing the task as a timed event through the
Fade
image softWare. In this respect it is necessary to develop the
positional matrix function and apply scalar multiplication
Function 1
Function 2
Function 3
Function 4
+/— 4 bit
+/— 4 bit
+/— 4 bit
+/— 4 bit
Full on
+ 8 bit
Full off
0
based on the initial spatial coordinates and the revised
‘MOVETO’ position. It is necessary to add also any revised
rotational information from the PUI to the MOVETO
matrix.
*Note that pan compensation is not strictly a function of tilt, but is high
lighted to illustrate the correlation.
Keystoning. Whilst it is possible to apply automatic
correction using the spatial coordinates already input, it is a
the graphics functions, taking in the image and performing
CPU and Image Handling
CPU Function. The CPU acts as the main processor for all
15
the required algorithms to achieve the desired output. The
very rare occurrence to operate a shoW in a plain rectangular
inputs comprise positional information, attribute override
(or square) box With the stage at ?oor level. Thus any
and graphics. The output is either graphics only if a remote
PUI is used, or all six attributes plus graphics.
Feedback to the CPU is required giving actual status
automatic correction Would be invalid if the unit Were
projected on any surface other than the ?at ceiling, Walls or
?oor. It is a primary requirement therefore to adjust the K
according to the surface projected onto at the time.
It is possible to set up a closed loop feedback using a four
axis range ?nder but such technology and development is
generally regarded as expensive in a system as described.
It is further possible to perform any correction automati
cally based on spatial coordinates and the MOVETO
command, as it may need correcting depending on the plane
of the projection surface. Such a tool is useful in straight
information of all six attributes so that a fast and accurate
imagezposition calculation can be performed. This also has
the bene?t of accounting for any external errors that may
occur.
Whilst such feedback is ideal, it is not strictly a require
25
forWard sets and so it can be treated in the same manner as
R With auto correction and manual override.
The output matrix to either the softWare or opto
mechanical K correction (Whichever is chosen) is depicted
in FIG. 6.
From the diagram it can be seen that around the Zero
reference datum a vertical correction requires adjustment of
—x3+x4 and —x1+x2. Similarly, for a horiZontal adjustment
the correction needs to be —y3+y4 and —y1+y2. Using the
folloWing positional matrix a transformation can be applied
35
shoWn in FIG. 7.
Fade. The fade is a fairly straightforWard function of the
calculable response time dependant on speed and ?nal
location of the command, and assuming that the system is
satisfactorily damped, the control function for such a move
(based on criteria such as inertia and input slope) can be
applied to any image as a transformation speed. This applies
to any image Where the MOVETO command is a point to
point command, i.e. move from xlylz1 to x2y2Z2. It Would
not be applicable to the duration of a continuous rotate, only
the start and stop instruction.
CPU Speed. The CPU is capable of calculating the neW
positions of multiple attributes concurrently, or at least very
fast, as Well as performing processor intensive functions
either based on the angle of the pan and tilt axes or using a
positional matrix derived from the MOVETO command,
and the result output to the imageering softWare.
Where x‘y‘ is the corrected value, and 6x by 61 are the
change in locator from the spatial preset the function is as
ment. When a MOVETO command is received, there is a
40
such as image rotation (should a softWare option be taken).
An indication of the speed required could be gleaned from
looking at the speed of the triggers. Assuming that the
attribute commands come from the lighting desk Which is
outputting DMX512, and that no attributes are set to ‘auto’,
the Worst case Would be as folloWs.
45
graphics engine. A single 8 bit channel gives smooth fading
Video Imaging. There are tWo Ways of calling up from the
image bank. The ?rst is to have a library of images or video
clips accessible from the lighting desk. Each of the OxFF bits
of a channel could relate to OxFF memory locations in the
betWeen full on (OxFF) and complete blackness (0x00). If
CPU Which in turn contain an image such as a gobo or a
the projector is run in RGBS or composite video the image
video clip. The programmer Would then call up said location
softWare may not be able to cope With a fade to black—the
options are then to use a mechanical dimmer Which adds
complexity or to fade to an external black burst generator.
as part of a cue.
The alternative is to use a channel or tWo as cue triggers;
the images and clips are assembled as a shoW in themselves
With each change of image given a marker on the timeline.
Such markers Would be activated on the change of state of
Table of Functions Required
Attribute
Pan
Function 1
Focus
Zoom
Function 3
— 12 bit
Rotate C (C) Rotate CC (C') Pan compensa
+ 12 bit
— 12 bit
Increment
Decrement
+ 4 bit
— 4 bit
Increment
Decrement
+ 4 bit
— 4 bit
Rotation
Increment
Decrement
+ 12 bit
— 12 bit
Keystone
X1Y1
X2Y2
the DMX channel, e.g., a change from OxAA to OxAB moves
the image softWare to the next trigger mark.
Further variations and modi?cations Will be apparent to
one of skill in the art Without departing from the spirit of the
invention.
What is claimed is:
Function 4
Rotate C (P) Rotate CC (P')
+ 12 bit
Tilt
Function 2
55
tion" +/— 12 bit
1. A lighting control system comprising:
means for directing an image beam in a plurality of
directions;
an image source;
65
X3Y3
X4Y4
an image processor capable of applying image corrections
to images from the image source to provide an input
from Which an image beam is generated; and
US 6,765,544 B1
15
16
4. A system according to claim 1, Wherein a user can
a computer controller having a user interface enabling a
de?ne an image transform to assign to a given image beam
user to assign, for each of a plurality of beam directions
corresponding to a series of desired image effects, an
movement.
5. A system according to claim 1, Wherein the computer
image correction such that the desired image effect is
displayed on a vieWing surface;
controller includes an image transform store and Wherein a
user can de?ne an image transform to be stored in said image
Wherein the computer controller includes a schematic
store.
timeline, and Wherein a user can pre-program a
6. A system according to claim 1, Wherein the computer
sequence of image beam movements and correspond
ing image transforms in a time sequence by de?ning
cues on said timeline.
controller includes a look up table and Wherein a plurality of
10
image beam movements and corresponding image trans
forms can be stored in said look up table.
2. A system according to claim 1, Wherein the means for
directing the image beam comprises ?rst and second move
previeW screen to provide a visualisation of an image
able re?ectors, the image beam being de?ectable by the ?rst
transform to a user.
re?ector on to the second re?ector so as to de?ect the beam
in a plurality of directions onto at least one vieWing surface.
3. A system according to claim 1, Wherein the computer
controller includes an image transform store and Wherein a
user can select a pre-programmed image transform from said
transform store to assign to a given image beam movement.
7. A system according to claim 1, further comprising a
8. A system according to claim 1, Wherein the image
15 transforms include a rotation.
9. A system according to claim 1, Wherein the image
transforms include a keystone correction.
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement